Draft gear



May 16, 1933. E, H. SCHMIDT DRAFT GEAR Filed Nov. 14, 1930 2 Sheets-Sheet l May 16, 1933. E. H. SCHMIDT DRAFT GEAR Filed Nov. 14 1950 2 Sheets-Sheet 2 V awve/wtoz 851g glib Patented May 16, 1933 UNITE s ss aren't oFFicE ERNEST H. SGHMIIDT, OT E CLEVELAND HEIGHTS, OHIO, ASSIGN'OR TO NATIONAL MALLE- ABLE AND STEEL CASTIN GS COMPANY, OF CLEVELAND, OHIOyA CORPORATION OF OHIO DRAFT GEAR Application filed. November 14, 1930. Serial No. 495,572.

This invention is concerned with the provision of a novel and improved railway draft gear. .The invention includes a novel arrangement of springs for cooperating with wedging and friction elements, and providing a high frictional and spring capacity. A further feature resides in effective provision for preventing the springs from being subjected to oversolid blows. Other features of the invention will be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a view partly in side elevation and partly in vertical longitudinal section of a draft gear embodying my invention, the usual draft gear follower being indicated in dot-dash lines.

Fig. 2 is a front end "elevation of said draft gear." Y

Fig. 3 is a side elevation showing the draft gear compressed, and with the follower in dot-dash lines.

' Fig. 4 isa view in horizontal section taken on line IV-IV of Fig. 2.

Fig. 5 is a transverse vertical sectional viewon line V.V of Fig. 4.

Referring to the drawings, the gear comprises a case 2, preferably rectangular in form in opposite walls 3 of which are seated the friction members 4, each of which is preferably a rectangular block having at its inner end a lateral projection 5. In each Wall 3 is a recess 6 in which the projection ,5 of the associated friction member 4 is seated. To resist the inward thrust of the friction members 4, the case 2 at the rear of the recesses 6 has abutments 6 against which the members 4 bear at their rear ends, and said abutments 6 are braced by ribs 7 which extend back to and are merged into the rear end 8 of the case.

On opposite sides of each of the friction members 4 and in frictional engagement therewith are arranged friction shoes 9, two friction members and four shoes being provided. The inclined forward faces of the shoes 9 areengaged by correspondingly inclined faces 10 of a wedge member 11;

Mounted centrally within the case 2 and extending along the longitudinal axis there of is a pair of spring coils 12, 12, one surrounding the other. The inner coil 12 bears at one end against-the rearwall of the case and at its other end directly against the wedge 11, said coil being received within a central recessed portion 13 of the wedge. The outer coil 12 engages the rear wall 8 of the case 2 atone end and at its other end engages a pair of followers 14, 14, each of which followers engages the rear faces 15 of the projections 16 of a pair of the shoes 9. As shown in Fig.5 each follower extends from a shoe cooperating with one of the friction members 4 to a shoe cooperating with the, other of said. friction members. Surrounding the central spring coil 12 'afore 9, and'positioned in the respective corner portionsv ofthe case,'as'shown 'in'Figs. 2 and 5.- Eachof said'springsi 17ibears at its rear end against the end' wall 8.: .At their forward ends, two of said springs engage one of the followers 14 and theother two of said springs engagethe other of said followers.

The case 2 and wedgell are maintained in assembled relation toeach other by means of a pair of bolts 18, 18, each of which at their rear ends are engaged with'openings in the wall-18 of the case as indicated in Fig. 4 and at their forward ends extend through the end walls 19, 19 of recessed portions or pockets 20, 20 in the wedge. Nuts 21, 21 are threaded on the forward ends of said bolts within said pockets. The followers 14, 14, are providedwith openings 22, 22 through whichthe respective bolts 18, 18 are passed. l

The portions 23 of the shoes 9 which extend rearwardly of the projections 16 are recessed as indicated at 24 to provide clearance forthe respective springs 17 It will be seen that compression of the gear is resisted by the springs 12 and 17, by the inner. spring coil 12 acting directly against the wedge, and by'thefriction generated between the shoes 9 and the associated friction members 4. Said shoes, under the influence of the wedge surfaces 10 and the action of the springs 12 and 17 ,are maintained in firm frictional engagement with the friction members during the compression of the gear. The amount of friction developed between the shoes and friction members is dependent on the angle of inclination of the sides of the friction members to the longitudinal axis of the gear. The faces of said friction members may, as shown, be parallel to said longitudinal axis or may be inclined with respect thereto.

By the provision of the four springs 17 and the central spring 12 a gear of high spring capacity is obtained and the action of these springs upon the shoes 9 results in the attainment of a high frictional capacity.

The inner coil 12, in addition to opposing inward movement of the wedge 11, insures release of the latter when the pressure on the gear abates. The parts following said abatement of pressure, are returned to their normal positions by the action of the various springs.

The extent of movement of the wedge with respect to the case is such that just before the springs go solid the peripheral flange 25 of the wedge will engage the front end of the case. The flange 25, as shown, is interrupted at the pockets or recesses 20, and it will be noted that the portions of the end of the case 2 opposite said recesses 20 are not engaged by the flange 25. I provide for utilizing the entire forward end of the case for taking up oversolid blows, for which purpose I have shown the portions of said end opposite the recesses 20 extended forwardly at 26, 26. The extensions 26, 26 are of such length that they extend through the interrupted portions of flange 25 and are engaged by the follower 27, as shown in Fig. 3, at the same time that the flange 25 engages the remaining portions of the front end of the case. The follower 27 is of the usual type and cooperates with the wedge 11 in the customary way. It will be seen that by providing the extensions 26, 26 for engagement by the follower concurrently with the engagement of the wedge with the other portions of the forward end of the case, I avoid the imparting of oversolid blows to only a portion of the case and instead distribute said blows around the entire front periphery thereof. The springs are thus effectively protected against oversolid blows and at the same time the full periphery of the forward end of the case is utilized for receiving such blows.

WVhile I have shown the projections 5 of the friction members in firm engagement with the openings 6, a limited amount of clearance may be provided between said openings and projections. In this way the initial compression of the gear may be opposed simply by thesprings 12, 12 and 17, and further compression thereof both by said springs and by the friction developed between the shoes and friction members.

The extent of preliminary spring action may be varied by varying the amount of said clearance, and the capacity of the springs.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim: 7

1. In a draft gear, a case, friction shoes in said case, friction means engaged by the shoes, springs compressed by movement of said shoes, a wedge engaging said shoes, said wedge being engageable with the case for protecting said springs against oversol id blows, retaining bolts connecting said wedge and said case, said wedge having cut-away portions receiving said bolts, said case having projections adjacent said cut-away porions for engagement by a followerin response to oversolid blows concurrently with said engagement of said case by said wedge.

2. In a draft gear, a case, friction shoes in said case, friction means engaged by the shoes, a wedge engaging said shoes, springs in said case resisting movement of saic shoes, a spring in said case engaging a central recessed portion of said wedge, retaining bolts connecting said wedge and'case, said wedge havingpockets recelvlng said bolts, a flange on said wedge engageable with the adjacent end of the case to protect the springs against oversolid blows, said flange being interrupted at said pockets, and means on said case adjacent the interruptions of said flange for engaging a follower concurrently with the engagement 'of said end of the case by said flange.

3. In a draft gear, a case; friction shoes within said case, wedging means engaging said shoes; a spring in said case and common to said shoes for resisting movement thereof; and other springs, one for each of said shoes, for resisting movement of said shoes, the last mentioned springs being positioned between the first mentioned spring and the sides of the case, and friction members extending inwardly of said case and positioned between said other springs.

4:. In a draft gear, a rectangular case, friction shoes within said case, friction members extending inwardly of said case and being engaged by said shoes, a spring centrally located in said case and common to said shoes for resisting movement thereof, and springs individual to said shoes and positioned in corner portions of said case for resisting movement of said shoes, certain of said springs being on opposite sides of said friction members.

5. In a draft gear, a case; friction shoes within said case; a wedge engaging said shoes; a spring in said case and; common to said shoes for resisting movement thereof; other springs, one for each shoe, for resisting movement of said shoes; the last-mentioned springs being positioned between the first mentioned spring and the sides of the case, a spring within the first mentioned spring and engaging said wedge, friction members in said case positioned between certain of said springs, and a pair of bolts extending respectively adjacent opposite sides of the case and being positioned between others of said springs for maintaining said case and wedge in assembled relation.

6. A draft gear comprising a case, friction shoes therein, a wedge engaging said shoes, friction members extending inwardly of said case and being engaged by said shoes, a plurality of springs, one for each shoe, for resisting movement of said shoes by said wedge, a spring'common to said shoes for resisting said movement, and a spring surrounded by said common spring and engaging the wedge, certain of said springs being on opposite sides of said fric tion members.

In testimony whereof, I have signed my name to this specification this 12th day of November 1930.

ERNEST H. $OHMIDT. 

